Guam Plants May Need to Upgrade Treatment

Jan 13, 2009

The U.S. Environmental Protection Agency on Jan. 7 proposed to deny renewal of the permit variances that exempted the Agana and Northern District wastewater treatment plants from full secondary treatment requirements.

“Today we have made a tentative determination that both wastewater plants do not meet the Clean Water Act requirements,” said Wayne Nastri, EPA's administrator for the Pacific Southwest region. “We welcome public comment on our proposal and will continue to work with the Guam government to protect the vital water resources of the island."

The Agana and Northern District plants are operating under a variance from secondary treatment. If the EPA’s proposal becomes final, the plants will be required to upgrade to full secondary treatment.

Both plants discharge treated wastewater that exceeds Territorial water quality standards for bacteria, which are designed to protect recreational activities such as swimming and fishing. The Guam Waterworks Authority also failed to provide information showing the discharges do not impair water quality. At this time, neither plant meets primary treatment requirements, which require 30 percent removal of total suspended solids and biochemical oxygen demand.

When secondary treatment is used, primary-treated wastewater receives additional treatment where a large portion of the organic matter in the wastewater is removed by making use of the bacteria in the sewage. There are a variety of different biological treatment techniques that allow the bacteria to consume most of the waste’s organic matter.

EPA’s tentative decision will be available for public comment through Feb. 27. A public hearing on the tentative decision will be scheduled based on input from the community. At the completion of the public comment period, the agency will consider all public comments and make a final decision on the variance application. For more information, visit http://www.epa.gov/region09/water/npdes/pubnotices.html.